Patent Number: 6,254,729

Title: Pulper with extraction plate assembly having removable inserts and method of manufacturing same

Abstract: A pulper for pulping a fiber suspension includes a vessel, an extraction plate assembly and a rotor. The extraction plate assembly is disposed within the vessel and includes a metal plate with a plurality of holes extending therethrough. A plurality of metal inserts are respectively disposed within the holes and project from the plate. Each insert is removably attached to the plate. A rotor is disposed within the vessel adjacent to the extraction plate assembly. The inserts are removably attached to the plate by brazing the inserts within the holes, or slightly shrinking the inserts using liquid nitrogen and placing the inserts in the holes.

Inventors: Doelle; Klaus (Appleton, WI), Lorenz; Kurt William (Appleton, WI), Wickesberg; Steve Richard (Reedsville, WI)

Assignee: Voith Sulzer Paper Technology North America, Inc.

International Classification: D21C 7/08 (20060101); B01D 29/01 (20060101); D21B 1/00 (20060101); D21C 7/00 (20060101); D21B 1/34 (20060101); D21C 007/00 (); D21D 001/00 (); B07B 001/20 (); B07B 001/49 (); B01D 029/07 ()

Expiration Date: 07/03/2018